Metal forming machine



April 14 1942 H.A A. .BERLINER ETAL 2,279,965

METAL .FORMING MACHINE Filed March' 30, 1939 Parent-d Apr. 14, 1942 c 2,279,965V n METAL FonMlNG MACHINE nem-y A. Berliner ana christian pe Boer. Wasn ington,v D. C., assignors to Engineering and Be(- searoh Corporation, Riverdale, Md., a corpora,-

` tion of Maryland Application March' so, 1939, serial No. 264,903

3 Claims. (Cl. 153-32) This-invention relates tov metal forming ina-- .chines and more particularly to the formation of sheet metal into various shapes.

.In forming metal sheets, and particularly where a relatively small number of any given shape is desired, presses have been employed in which the edges of `a sheet are clamped and a form isr pressed into the sheetto stretch and form it into the desired shape. One such Vpress is disclosed in the copendingapplication of Henry A. Berliner Serial No. 233,726 filed October 7, 1938.

With presses of this type forms must be employed which are entirely convex and no concave shape is possible except. in a line transverse to the line between the clamps. Difficulty may also be encountered with forms having convex portions and straight portions or portions of varying convex curvature in getting the metal to shape'I itself closely .to the form.

It is accordingly one of the objects of the invention to provide a machine and a method for forming metal sheets into shapes including portions of different convex curvature, one or more According I to one important feature this is accomplished by f of which portions may be concave.

providing an outer working sheet over the form with the sheet to be formed lying between the :form and the working sheet. A mass of rubber or other gum or plastic material may be placed between the sheets at the point or points where a concave or relatively concave curvature is to against the form.

In machines of this type it has been the usual practice to clamp the sheet to be formed and then press the form into it. This necessitates a considerable amount of trimming which may,

materials, result in a serious waste problem.

It is accordingly another object of the invention to provide a forming machine and method in which trimming is minimized or entirely eliminated. This may be accomplished by using a workingL sheet which presses the sheet 'to be formed against the form. In this way the sheet to be formed' need not be clamped and may be madesmaller so as to reduce or eliminate trimming.

Still another object of the invention is to provide a forming machine and method in which the sheet to be formed is frictionally held in place on the form. This is preferably accomplished by providing a depressed or cut out portion in the pattern to receive a portion of the sheet and hold it'against slipping. According to vbe produced to press the inner sheet closelyV -in the case of some of the more expensive sheet one important feature this cut out portion may bein' the form of an elongated slot to receive the edge of the sheet so as to anchorthe sheet along said edge and to form an angular iiange thereon.

Other objects, advantages and novely features of the invention will be apparent from the following description of the embodiments illustrated in the accompanying drawing, in which:

Figure 1 is a partial side view with parts in section of a machine embodying the invention;

Figure 2 is a similar view showing the machine with a different form or pattern thereon; and

Figure 3 is a perspective view of the sheet and pattern of Figure 2. l

The illustrated `machine includes a pair of elongated spaced beams lll having cross beams 1 I2 slldably mounted thereon. Each of .the beams I2 carries a plurality of clamps I4 individually adjustably secured thereto, which clamps may be operated by fluid under pressure admitted through pipes I6 as is more fully described and claimed in said copendingv application Serial No.

233,726. Each clamp includes a pair of jaws I3 vadapted to grip the edge of a sheet of metal or the like.

Between the beams I2 .there is arrangedV a plunger 2li adapted to be moved upwardly under hydraulic pressure or the like. The plunger hasverse section vof the form may be of 'any desired shape and will generally be in the form of a curve such that a double curvature is presented.

According to the present invention a working sheet 30 which may be of steel or any other strong but relatively exible material is clamped at its ends in the jaws I8 and extends across the form. A sheet 32 to be Aformed and which may be steel, aluminum or any other desired metal or alloy is placed over the form under the working sheet '30. The sheet 32 may have its vends clamped in the jaws I8 with the sheet 30 or may be secured by separate additional clamps but is preferably laid loosely' over the form with its ends free as shown.

In order to press the sheet 32 into the concave portion 26 of the form, a block of yieldable material 34, shown as rubberkis arranged between the sheets 30 and 32. `This block may be loose or may be cemented or otherwise secured to the placement. Also by cutting the sheets to be formed tothe cOrIect--initiaIshaPeaLl n ,g inpiig'ivi 11 *Whenthe' `plunger 20' is raised, it presses the may be avoided butdnany Y'eve''riiiri sheet 32 into the sheet 30 andl against the block be very much reduced. 34 so that the sheet 32 is pressed closely against '5 It will furtherl be understood that the drawing ythe form or pattern 24 and is'shaped to conform and above description are illustrative only and thereto the metal of he work` sheet being caused are not intended as a denition of the scope of to iiow between the pattern and the sheet 30 the invention, reference being had for this purto conform to the double curvature of the patpose to the appended claims. v

' tern during this operation. The use of a yield- 10 What is claimed is:

able blokf eliminates'ftlie necessity' accurate' formatinf thereof"J whileinsuring ffthat the "s'heet l will be pressed closely against the form. Pressthereto, a flexible, non-resilient forming sheet ing of the sheet into the cut-out concave portion hving its edges iixedly secured on opposite sides 26 also anchors the sheet against.sslippingion.15oftheheadjand having its central portion disthe form as it shaped. "posedithepath of the head and arranged in ``xthezv approximate' shape of the form, and means y or"-movi'ng"'the"liead and form toward the form- "ir'g`sli tf' hereby Ifa Work sheet positioned bebe employed in forming edge strips'` for an air- 20 twen the frnif-and the forming sheet and plane wing is secured to thegheadg22nf An elo 5 which-is Vtohaveithe shape 0f the fOlm iS degated narrow groove 38 is formed in thezpattgrn formed VVbetween the form and the central part of 36 adjacent one edge thereof to receive *c` x`1`e"edge'-"' vtlfrx'riing sheet.

ofa'sheetu,4l lto,be;formed.ff1-f1.9 r ne l 2,- Alsheet metal forming machineaccording qiInuoperatingthisqembodirnentI thefedge .of va '25 to claimLin-vvhich.thevforin,is'provided 4 vv'itha sheet lll/is finsertedzmr-.ihe vgrooveji pand?. the slot within which'anied'gaoifthe sheet may.; if.l desired; be;bentfovenslightlyfto: adoptedgtogbe reoceivedjA .f l ward'the surfaceof the pattern 36; The plunger v i ysheet* mtal, forr'ingflmachine'l according 20.1may then be-fraisedrto -pressgthe form :and tolfclaim linfyvhicha' fornii having' 'ahconcave thefsheet lll-fintoy the.. working 7sheet-:illuso -`that 30 portion and ,a convex` portiony is attachedto 'the the sheet. All; will. be; pressed closely; around gthe movable. head, V andir in which,v a mass 4onf 'fyildable form.- ',Theigpressuregof the Working 'sheet-i on material ijiisposeclll interiorly'` oithe forming theheetf 48.:adjacentythegroove; 38 locks ythe sheetat thepart thereof` |adjacent, theoncve sheet; 40 on;the; form to Aprevent slipping thereof portion of .the 'forn1, wherebyfa wo'rk sheet'posiandA the portion of sheet lvextendingxintoithe 35 tioned `between the forming sheet andthefdorm groove 38 may be trimmed oi or may be-'retained vv'll` Vbe forced intor the lconcave rportion of the asa aStening-iange. v. f. `form.bythemass of` yleldablematerial.` It will be understood thatthevformingsheets g1 .n ,1, VHENRY A. BERLINER! '.30 may be used a-numberof timesLwithout rei t .CHRIS'l'IAN`DEIBOlill'tQ-V 

